GP2X Ext Port


MiniMoose

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I was looking at the u-boot source on the open2x cvs server and noticed that the version from MagicEyes includes support for UARTS (serial ports). We really need to get the version from GPH to figure out which UART the shipped UBoot version supports (if at all).

I was wondering if anybody has any close-up pictures of the GP2X's EXT port without the cover in place. I want to see the pin arrangement. I know that the wiki says that there are UARTs, JTAG, and DAC outputs in the 24 pin port. Has anybody figured out which pins are for what purposes?

If I can get a picture of the pin arrangement, I'll probably be able to track down a source for connectors so that I can build a serial "coder's cable". Using u-boot you can upload executables over the serial cable into RAM and execute them. This would be the way to get around the Linux kernel for development purposes, though I don't think you would be able to ship a game like that since the GP2X boots into Linux by default and not your game.

Anyway, anybody got any more info on the EXT port.
 

Squidge

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If all you want to do is build a serial or jtag cable, then just ask for a snapshot or two of the dev board serial hardware, as this plugs into the ext port and provides uart and jtag support. If you want to play around with uboot, then you need to just send characters down the serial port about 100ms after switching it on. This is the way we are testing our pre-linux code.

Do note however that the UARTs are 0-3v, so you'll need a max232 (or similar) and associated components for use as a level shifter.
 

MiniMoose

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If all you want to do is build a serial or jtag cable, then just ask for a snapshot or two of the dev board serial hardware, as this plugs into the ext port and provides uart and jtag support. If you want to play around with uboot, then you need to just send characters down the serial port about 100ms after switching it on. This is the way we are testing our pre-linux code.

Do note however that the UARTs are 0-3v, so you'll need a max232 (or similar) and associated components for use as a level shifter.
Can you post pics of the port/cables? I know you've got a dev unit. We're going to need serial coder's cables once we get our units, even if it is for debugging.
 
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DJWillis

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Can you post pics of the port/cables? I know you've got a dev unit. We're going to need serial coder's cables once we get our units, even if it is for debugging.

I can post up some pics if Squidge is busy, I think at least one company that does GP32 leads is going to do a jTAG and serial breakout set for the GP2X if not a lot more. And running raw code via U-Boot is just what we have been doing since day one ;). The idea is to take is some steps further and make it much more 'end user' friendly.

The serial board is very simple to make, the hard thing is the EXT connector, the only source I found wanted a 5k min order before shipping samples. I'll dig the link and info out on Monday as it's on my work PC.

The serial board also had pads to wire up a jTAG setup but you would need do some scope work to check all that out and I don't have a decent scope.
 
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triton

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one think i want to know is the pinout for the video cable, waht pins it uses, so i dont have to spend 10$ on a special cable for TV out, paying 200+ an SD card is plenty for me, anyone have info on this?
 

Vimacs

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i dont think the total for the connectors will be much lower than 10$ when you just buy 1 (if you can even get a single one)
 

triton

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i would probably make the connector my self if at all possible, i have no idea what the ext port looks like tho
 
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